Process of refining oils



Patented July 7, I931 'HUNITED STATES PATENT OFFICE WILLIAM T. BRYANT,01'! HOUSTON, TEXA S, ASSIGNOB TO W. A. WILLIAMS, OF

, HOUSTON, TEXAS PROCESS OF BEFINING OILS I No Drawing. Applicationfiled August 30, 1927. Serial No. 216,496.

. The ordinary sulphuric acid treatment stock is neutral to anindicator. At this and clay treatment of distillates consists in point,clay is added to the oil and the mixplacing the distillate in anagitator and ture is heated to a desired temperature, adding thereto, asuitable amount of sul- While passing through the heat exchanger 5phuric acid, the amount depending upon the coils, or other heatingdevices. In both character of the distillate to be treated. methods, theoil is heated in the presence The oil and acid are thoroughly agitatedof clay. WVhen operating as per Method by means of air, so as to causethe sulphuric 1 or 2, or both, the following difliculties acid to bethoroughly mixed with the disare encountered: I tillate. The result ofthis treatment is the In order to obtain a highly efficient transremovalof tar and other impurities. The fer of heat from a heat exchanger, itis necremaining sludge acid is drawn oi'i together essary to use smalldiameter pipes or tubing. with the tar and other impurities, that Thenusing small coils, considerable diffisettle to the bottom of theagitator. The culty is encountered by plugging or stopacid oil, afterthe acid sludge, tar, etc., have page, due to clay settling out of theoil, or been removed, is transferred to a clean agicollecting in variousparts of the exchanger. tator. In this agitator, the acid'remainingAlso, to obtain an eflicient heat transfer, in the oil is neutrlized'with a weak solution the mixture has to be passed through the ofcaustic, such as sodium hydroxide or coils at a relatively highvelocity. The high sodium carbonate. After the stock is thorvelocity ofthe mixture causes a rapid deoughly neutralized, the remaining alkali ispreciation of equipment, due to the cutting removed from the stock byprocess of setand abrasive action of a solid material contling andwashing with hot water until the tained in the oil. Also,'it the clayand oil I distillate tests neutral to an indicator. The mixture is notkept in rapid motion, or at oil, after the alkali'treat has beencompleted, high velocity, the clay will settle out, thereis transferredto a'large diameter, but rather by causing stoppage of flow. When largea shallow tank. In this tank, any remainvolumes of distillate are beingprepared for ing water that will settle, is removed, and clay treating,the distillate has to be kept the small traces of water still remainingin agitated in the mixing tank, or else a settlethe oil are removed byair blowing, or else ment will occur that will in due time form by meansof a vacuum, as per my co-pending a hard cake of clay which is not veryeasily application, Serial No. 153,944. The above removed. I method isthe 'usual and generally used Moreover, when the clay and oil mixturemethod of treating lubricating oils with is heated, and the clay kept incontact with acid, and alkali. the oil at or above the reactiontemperature, V When the distillate is to be clay treated, it isnecessary in operating by this method, two methods are commonly used.The first to guard against reverse action, which seems method consistsin treating the hydrocarto take place. That is, a portion of a debonswith sulphuric acid, withdrawing the colorizing material absorbed orotherwise -0 acid reaction products, (eliminating the alheld by the clayreverts back to the oil, kali treatment), adding to the treated acidthereby lessening the efficiency of the bleachhydrocarbon a decolorizingclay of approxiing material. 'mately 200 mesh fineness, and insufiicient My improved method of bleaching hydroquantity to obtain thedesired color. The carbon oils consists of clay treating the disefi clayand hydrocarbon mixture is passed tillate after acid treatment andneutralizthrough a heat'exchanger, or heater coils, or ing with causticor other alkalis. This disothersuitable heating device. tillate iswashed until it is neutral to indi- Method #2 consists of neutralizingthe cator test. 1 acid hydrocarbons with an alkali, removing Thedistillate ready for the clay is passed 5 the surplus alkali, andwashing the oil until through a heat exchanger (designed for eflioil isheated to the desir ence of clay. a temperature mper'ature WithExperiments have shown that Fahrenheit to procedure eliminates thenecessity of heating theoil up to a desired reaction temperature beforeadmitting the clay.

t Will be seen that by myprocess",- Soon as the oil enters the agitatingtank the clay may be added.

Moreover, since the oil is at the proper reaction temperature,thereaction of the maximum temp e approximate this case would Whereasthe mini-l clay With the oil is immediate and filtering can be. at oncecarried on.

perature Would be approximately T 1011 is governed the typeof clay iromthe heat e2; ger orpipe coils, passe maybe maintained. at ed temperaturehe mixing tank, a y 18 added to 'tated. Any Uion canv'be i-ned amount 0'lhe process is rapid, simple and thorough, and overcomes thedisadvantages which have heretofore been attendant upon the decolor-011s ai'ter chemical treatment. it

Will be noted in t 1s process, that theoil no oil afte o p mpin from f ithe bottom nk into the top ove the liquid level. V

decolorizing clay .form, althou moisture conte "lays usually coi lch;iscomb nts may be itain 10 to for a period the oil and cla or in heatingthe oilzup to a temperature for contact with theclay. By having the oilatthe propertemperature or decolorization, the clay immediately reactsand filtering 1823A? once started.

be flushed 'OI' sluiced out .of'l the -chambers by a flow of Water,This, permits cleaning of the filter Without dismantlingthe appart \ivilltherefore be understood that sub y stantiallycontinous filtering canhev achieved with my process. This 1s'-. desi-rable not only from thestandpointof recovering the oil event reversion, but, moreover, becauseit i 7 here thecl F, ture, ,and in to d reaction and th I .mi xing tank.It is to,be,-'obser n t ally i its passage t e oil is'heated con a W hepresent quality of the 0 very materially. s V v he fact that a smallquantiy of Water process improves both the y eld, and asWill beunderstood, there will e no. objectionable effect upon th ia d, aspreviously stat rature from 24 tus; e' time of operations is material-lshortened, sincethe process 18 continuous.

here prev ous decoloriz ng methods af-: ,ter ch em1cal treatment havebeen compl1cat rrc e s n by ed and expensive, the present ;method, en-

ables theoil: to be claytreateduponits dis charge from the heatexchanger-andat once Isubjectedf to filtering,

smeans' to sustemperature.

:ber' iprovided V ith' heating :the oil at th lland the, quantity or" 1What I claim is:

The process of treating oil which comprises subjecting the oil to acidtreatment and removing the sludge, heating the oil above 212 F. andbelow its flash point, delivering the oil so heated to a clay treatingchamber and maintaining it at elevated temperature, adding the clay tothe oil While at said temperature to cause substantially instantaneousreaction of the oil and clay, agitating the mixture, immediatelyconducting the oil from the chamber through a continuous filteringmeans, and subjecting the filtered oil While in heated condition to theaction of a Vacuum, removing the moisture by Volatilization, thetemperature of the oil being sufliciently high to cause vaporization ofany Water contained in the oil at the particular pressure utilized. 7

In testimony whereof I have hereunto set my hand.

WILLIAM T. BRYANT.

